Revert "USB: don't explicitly reenable root-hub status interrupts"
This reverts commit e872154921a6b5256a3c412dd69158ac0b135176.
Andrey Borzenkov reports that it resulted in a totally hung machine for
him when loading the OHCI driver. Extensive netconsole capture with
SysRq output shows that modprobe gets stuck in ohci_hub_status_data()
when probing and enabling the OHCI controller, see for example
http://lkml.org/lkml/2008/7/5/236
for an analysis.
The problem appears to be an interrupt flood triggered by the commit
that gets reverted, and Andrey confirmed that the revert makes things
work for him again.
Reported-and-tested-by: Andrey Borzenkov <arvidjaar@mail.ru>
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Acked-by: David Brownell <david-b@pacbell.net>
Cc: Greg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/drivers/usb/core/hub.c b/drivers/usb/core/hub.c
index 512d2d5..4cfe32a 100644
--- a/drivers/usb/core/hub.c
+++ b/drivers/usb/core/hub.c
@@ -2073,6 +2073,8 @@
}
clear_bit(port1, hub->busy_bits);
+ if (!hub->hdev->parent && !hub->busy_bits[0])
+ usb_enable_root_hub_irq(hub->hdev->bus);
if (status == 0)
status = finish_port_resume(udev);
@@ -3002,6 +3004,11 @@
hub->activating = 0;
+ /* If this is a root hub, tell the HCD it's okay to
+ * re-enable port-change interrupts now. */
+ if (!hdev->parent && !hub->busy_bits[0])
+ usb_enable_root_hub_irq(hdev->bus);
+
loop_autopm:
/* Allow autosuspend if we're not going to run again */
if (list_empty(&hub->event_list))
@@ -3227,6 +3234,8 @@
break;
}
clear_bit(port1, parent_hub->busy_bits);
+ if (!parent_hdev->parent && !parent_hub->busy_bits[0])
+ usb_enable_root_hub_irq(parent_hdev->bus);
if (ret < 0)
goto re_enumerate;